In general, a transmission network for transmitting analog signals, digital voice signals or digital information is composed of a variety of complex connection devices. As the network environment is shifted to multimedia network, network-related techniques become extensive and networks are connected through complicated routes. Accordingly, devices in various forms are used to facilitate signal processing. Such devices are usually located in an area where a plurality of installations, such as telephone repeater stations, are placed, the installations being connected to each other through various methods including coaxial cables, microwaves and artificial satellites.
In a transmission network, one of the most important functions is to connect one device to another device. The connection of two devices is typically achieved by a first terminal device received by a plug, cable or other carrier, connected to another terminal device through another plug, cable or carrier. The connection device may include additional devices for monitoring or testing.
The cables of the network devices are connected by a jack which distributes the digital signals and electrically connects and disconnects the signals as they are processed. Such a jack typically includes a jack housing, a printed circuit board, conducting wires, a plurality of sleeves for receiving corresponding plugs, and a switch. The plugs at the ends of the connecting cables are inserted into the sleeves of the jack to connect the network devices to each other. A known configuration of a conventional jack for distributing digital signals for connecting network devices is described below. FIG. 1 illustrates the inner configuration of the conventional jack for distributing the digital signals, and FIG. 2 is an enlarged plan view of the switch of the conventional jack.
Referring to FIGS. 1 and 2, the conventional digital signal distributing jack 1 includes a plurality of sleeves 12 into which corresponding plugs 40 are inserted, sleeves 12 being assembled within a jack housing 10, a plurality of conducting wires 20 and 22 connected with plugs 40 when plugs 40 are inserted into sleeves 12, and a switch 30 assembled within jack housing 10 for electrically connecting or disconnecting conducting wires 20 and 22.
Conducting wires 20 and 22 are arranged within jack housing 10 for conducting electrical signals, and their ends extend to the center of sleeves 12. Switch 30 for electrically connecting or disconnecting conducting wires 20 and 22 is composed of a contact terminal 34 which is movably supported in a plate spring at the rear of a switch body 32 to allow its end to come into contact with conducting wires 20 and 22, and an elastic piece 36 which is elastically supported at both sides of the front of switch body 32, the end of elastic piece 36 coming into contact with one side of contact terminal 34, elastic piece 36 having a contact 36a at each side.
In the above-described configuration of a conventional jack, when elastic piece 36 is deflected by plug 40 during insertion of plug 40 into sleeve 12, contact terminal 34 is disconnected from conducting wires 20 and 22 by elastic piece 36. By doing so, electric connection between the two conducting wires 20 and 22 is cut off. In this switch configuration however, the restoring force of the contact terminal deteriorates over time as the plug is repeatedly inserted into the sleeve.
Specifically, the contact terminal is in contact with the conducting wires when the plug is not inserted into the sleeve and it is disconnected from the conducting wires when the plug is inserted. However, the restoring force of the contact terminal is weakened due to repeated insertion of the plug, which can allow the contact terminal to disconnect from the conducting wires even when the plug is not inserted. This unintentionally cuts off the electrical connection between the contact terminal and the switch and therefore interferes with the intended switching of the signals.